减压氩气环境下激光显微光谱分析再现性和灵敏度的研究

Study of the Reproducibility and Sensitivity of Laser Microspectral Analysis in Argon Atmosphere at Reduced Pressure

以金属合金光谱分析标样为样品 ,采用激光显微发射光谱分析系统在减压氩气环境下 ,实验研究了光谱分析再现性和灵敏度。以原子线作为分析线的RSD减压氩气环境好于常压空气环境 ,以离子线作为分析线的RSD基本相同 ,样品的组成和元素的浓度对分析线的RSD有较大的影响。测定的铝合金样品Cu ,Zn ,Mg浓度曲线斜率是空气环境下的 1 5～ 2倍 ,表明分析灵敏度得到明显改善 ,有利于激光显微光谱分析范围的扩展。

In argon atmosphere at reduced pressure, the spectral analysis reproducibility and sensitivity are experimentally studied with the laser microprobe emission spectral analysis(LMESA) system for the metal alloy standard samples. For the atomic spectral analysis line, the relative standard deviation(RSD) in argon atmosphere at reduced pressure is better than that in air atmosphere. For the ionic spectral analysis line, the RSD is almost the same in both cases. The RSD is strongly affected by the composition of the sample and the concentration of elements. The measured slope of calibration curves for the determination of Cu, Zn and Mg in an aluminum alloy in argon atmosphere is about 1.5-2 times of that in the air atmosphere, which indicates an obvious improvement of the sensitivity and is helpful to expand the dynamic range of the spectral analysis.